Main reason had been some fixes to allow compiling with gcc5 and other c++11 compilers.

Here's the full change-list:

- Tests on Unix now have a short pause between switching drivers to avoid certain X11 errors. - Fix CEnumAttribute::getInt() which could crash (thx @ luthyr for reporting) - No longer try to run tests for drivers not supported on a platform - Update lights and renderTargetTexture tests to work with Windows 10 (can't have so tiny Windows anymore). - Deprecate CMatrix4::transformBox as the result is no longer a boundingbox. Use CMatrix4::transformBoxEx instead (which has been available for a long time). - Fix CSceneCollisionManager::getPickedNodeBB which could sometimes miss collisions. - Add -U__STRICT_ANSI__ option to c::b project files to allow compiling with -std=c++11 and add an error when trying to compile with Irrlicht with __STRICT_ANSI__ - Update libpng to 1.6.23 - Update zlib to 1.2.8 - Fix some compile warnings in aes which got handled as errors by some c++11 compilers. - Get rid of some misleading-indentation warnings in gcc6 - Fix serialization of the InputReceiverEnabled flag in CCameraSceneNode - Fix pasting text from X11 applications to Irrlicht. Thanks @est31 for the patch. - Tests give now a warning when stabilizing screenshots failed. Aslo trying more often now (a hack as taking screenshots otherwise fails often in windowed mode on some systems).

I no longer added the MinGW dll's as they tended to be incompatible anyway unless people used exactly my configuration. Instead updated the readme's for rebuilding a little bit.

One tiny error in changes.txt file in official version - it say libpng is updated to 1.6.21 as I forgot updating changes.txt again when I updated libpng once more yesterday. It's libpng 1.6.23 now.

@Vectrotek: Main reason is that we don't change functionality in bugfix releases. Basically you should be able to replace the dll without any chance of something in your application now messing up. The reason why it hasn't been replaced yet in trunk - we don't want to affect speed too much for everyone for a feature which only very few people need. And that might need some more work.